Authorities called off rescue efforts three days after a Latvian supermarket roof collapsed and killed at least 54 people.

The roof of the Maxima store caved in Thursday in Riga, Latvia, trapping shoppers in what Latvian President Andris Berzins called a “murder.” “This is a case which should be clearly named, that it is a murder of an enormous amount of defenseless people,” the president said in a television interview.

Emergency workers rescued some survivors amid the rubble in the immediate aftermath, but officials said Saturday no survivors had been found for a day.

The cause of the disaster is still unclear, but local media reported that workers had been building a rooftop garden.